Roller devices are often employed when moving objects in order to reduce the load and facilitate maneuvering. The roller devices may be directly attached to the object that has to be moved, either releasably or as an integrated part of the object. The object may also be placed on a support unit equipped with roller devices. Objects and support units equipped with roller devices and used for moving objects are often also required to be capable of assuming a stationary position.
One solution for achieving such a position will be to equip the roller devices with brake means. Particularly when using roller devices on objects where a high degree of stability is required, and especially where the objects in themselves are heavy or are carriers of heavy and/or unstable loads, it will often not be sufficient to equip the roller device with ordinary brake means. This applies particularly in connection with furniture elements and objects which have to remain stationary for a lengthy period.
It is therefore an object of the present invention to provide technical solutions whereby an object can both be moved and will be capable of achieving a position where the object remains stationary relative to the base.
An arrangement of this kind for permitting an object to both be moved and remain stationary is known from DE 198 01 509. In this publication a device is described for achieving easy displacement of a piece of furniture, using a roller body and a spring mounted in a sleeve which forms part of the leg of a piece of furniture. When the furniture is unloaded, the spring will push the roller body out of the chair leg into a position where the furniture can be moved. When the furniture is loaded against the ground, the roller body is pressed into the leg of the furniture and in this condition the furniture will remain stationary relative to the base.
In the solution disclosed in DE 198 01 509 the device is not equipped with means or arrangements for securing the roller body in the rolling position. A drawback of the solution disclosed in DE 198 01 509 is that if the furniture is loaded or the actual roller body meets an obstacle on the floor, the furniture's capacity to move will be diminished, since the roller body will be partly or entirely pushed into the sleeve.
EP 0153832 illustrates a furniture castor which can be moved between a retracted position and an extended position. The castor is attached to a rod connected to two elements with cam-shaped surfaces which control the position of the rod.
Both of the above-mentioned solutions are bulky and unsuitable for being fitted to many types of furniture, since they require too much space as well as spoiling the aesthetic appearance of the object to which they are attached.
The object of the present invention is to provide a solution which improves the disadvantages of the technical solution known from DE 198 01 509. In particular, it is an object of the present invention to achieve a solution which is small and compact and which ensures that during displacement the roller device is kept in a rolling position and is not unexpectedly pushed into the sleeve.